Examples of internal combustion engines of this type have been described in DE-OS No. 30 24 109 (U.S. Pat. No. 4,455,543), in DE-OS No. 35 00 530, and in DE-OS No. 35 13 107 (U.S. Pat. No. 4,682,574).
The internal combustion engines described therein have gas exchange valves which are moved from their opening to their closing position or vice versa by means of an electromagnet, which releases its hold on the gas exchange valve in one of its open or closed end positions when the electromagnet is either energized or de-energized. This, in turn, causes the gas exchange valve to move by spring suspension towards its other end position, where it is recaptured by a magnet.
In more detail, an anchor plate is suspended by opposed spring systems between a pair of spaced-apart electromagnets. The anchor plate is attracted and held by an electromagnet in one end point when energized. When de-energized the spring system moves the anchor plate back toward a centered or equilibrium position. The opposite electromagnet then attracts and holds the anchor plate in the other end position. The anchor plate can either be attached to the valve stem, or it may be held by a guide system so that a tappet member strikes the end of the valve stem and pushes the valve to the open position.
The opening or closing timing of the gas exchange valve can be predetermined by controlling the timing of the electromagnet.
It has nevertheless been shown that the exact moment of opening or closing of such electromagnetically actuated gas exchange valves is limited by an uncertainty factor, so that there can be irregularities in the operation of the internal combustion engine. There is a definite need in the art to improve engine operation and life through more precise control of valve operation.